Click the 'green flag' to start the project. Click the 'backdrop' to make it change colour effect by 25%. Click the 'cake' to play the 'Birthday Song' and also make it change size. Click 'Giga' (the red guy) to make him say 'Happy Birthday!' for two seconds. Click the 'Scratch Cat' (originally know by the name 'sprite1') to make him spin around (he'll face his regular direction when you press the 'green flag'). Finally, click the 'emoji' / 'smiley face' to make it say 'Celebrate!'.
Thanks to the Scratch team for the original game and the tutorial of how to make the game! If you'd like to make this game, click on the top of the Scratch home screen (Make a Birthday card) and on the right-hand-side of your screen; there'll be a slide. Open it to start the tutorial!